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| author | Stephen Finucane <stephen@that.guru> | 2018-04-19 13:57:22 +0100 |
|---|---|---|
| committer | Ian Stokes <ian.stokes@intel.com> | 2018-04-21 16:59:45 +0100 |
| commit | 31d0dae22a0ea1818c89e3a1d02ea515229bb1ad (patch) | |
| tree | a7350c2c7198c286bb6b05f6887f7326b15466cc /Documentation/howto | |
| parent | 6477dbb9d6560a3af2d63448fbe40ea6a2191788 (diff) | |
| download | openvswitch-31d0dae22a0ea1818c89e3a1d02ea515229bb1ad.tar.gz | |
doc: Add "PMD" topic document
This continues the breakup of the huge DPDK "howto" into smaller
components. There are a couple of related changes included, such as
using "Rx queue" instead of "rxq" and noting how Tx queues cannot be
configured.
Signed-off-by: Stephen Finucane <stephen@that.guru>
Signed-off-by: Ian Stokes <ian.stokes@intel.com>
Diffstat (limited to 'Documentation/howto')
| -rw-r--r-- | Documentation/howto/dpdk.rst | 86 |
1 files changed, 0 insertions, 86 deletions
diff --git a/Documentation/howto/dpdk.rst b/Documentation/howto/dpdk.rst index 69e692f40..cfa2d86a1 100644 --- a/Documentation/howto/dpdk.rst +++ b/Documentation/howto/dpdk.rst @@ -81,92 +81,6 @@ To stop ovs-vswitchd & delete bridge, run:: $ ovs-appctl -t ovsdb-server exit $ ovs-vsctl del-br br0 -PMD Thread Statistics ---------------------- - -To show current stats:: - - $ ovs-appctl dpif-netdev/pmd-stats-show - -To clear previous stats:: - - $ ovs-appctl dpif-netdev/pmd-stats-clear - -Port/RXQ Assigment to PMD Threads ---------------------------------- - -To show port/rxq assignment:: - - $ ovs-appctl dpif-netdev/pmd-rxq-show - -To change default rxq assignment to pmd threads, rxqs may be manually pinned to -desired cores using:: - - $ ovs-vsctl set Interface <iface> \ - other_config:pmd-rxq-affinity=<rxq-affinity-list> - -where: - -- ``<rxq-affinity-list>`` is a CSV list of ``<queue-id>:<core-id>`` values - -For example:: - - $ ovs-vsctl set interface dpdk-p0 options:n_rxq=4 \ - other_config:pmd-rxq-affinity="0:3,1:7,3:8" - -This will ensure: - -- Queue #0 pinned to core 3 -- Queue #1 pinned to core 7 -- Queue #2 not pinned -- Queue #3 pinned to core 8 - -After that PMD threads on cores where RX queues was pinned will become -``isolated``. This means that this thread will poll only pinned RX queues. - -.. warning:: - If there are no ``non-isolated`` PMD threads, ``non-pinned`` RX queues will - not be polled. Also, if provided ``core_id`` is not available (ex. this - ``core_id`` not in ``pmd-cpu-mask``), RX queue will not be polled by any PMD - thread. - -If pmd-rxq-affinity is not set for rxqs, they will be assigned to pmds (cores) -automatically. The processing cycles that have been stored for each rxq -will be used where known to assign rxqs to pmd based on a round robin of the -sorted rxqs. - -For example, in the case where here there are 5 rxqs and 3 cores (e.g. 3,7,8) -available, and the measured usage of core cycles per rxq over the last -interval is seen to be: - -- Queue #0: 30% -- Queue #1: 80% -- Queue #3: 60% -- Queue #4: 70% -- Queue #5: 10% - -The rxqs will be assigned to cores 3,7,8 in the following order: - -Core 3: Q1 (80%) | -Core 7: Q4 (70%) | Q5 (10%) -core 8: Q3 (60%) | Q0 (30%) - -To see the current measured usage history of pmd core cycles for each rxq:: - - $ ovs-appctl dpif-netdev/pmd-rxq-show - -.. note:: - - A history of one minute is recorded and shown for each rxq to allow for - traffic pattern spikes. An rxq's pmd core cycles usage changes due to traffic - pattern or reconfig changes will take one minute before they are fully - reflected in the stats. - -Rxq to pmds assignment takes place whenever there are configuration changes -or can be triggered by using:: - - $ ovs-appctl dpif-netdev/pmd-rxq-rebalance - QoS --- |